Browsing by Subject "Microwave sintering"

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    The effect of SiC content on microstructural and tribological properties of sintered B4C and SiC reinforced Al-Cu-Mg-Si matrix hybrid composites
    (Walter de Gruyter GmbH, 2022) Gezici L.U.; Özer E.; Sarpkaya I.; Çavdar U.
    In this study, B4C and SiC hybrid reinforced Al-Cu-Mg-Si alloy Matrix composites were fabricated using a microwave sintering technique at a sintering temperature of 550 °C for 60 min. In the produced hybrid composites, while the B4C ratio was kept constant (3 wt%), SiC was used in four different amounts (3, 6, 9, and 12 wt%). In these produced hybrid composites, as a result of microwave sintering, thanks to the high microwave absorption of SiC, the porosities closed at a rate of 36.65-40.90%. In 3, 6, 9, and 12 wt% SiC reinforced composites, the microhardness of 100.1, 106.8, 114.4, and 117.2 HV0.05 were achieved, respectively. Due to agglomeration increasing with SiC reinforcement rate, delamination wears increased in 12 wt% SiC reinforced hybrid composite. As a result, the lowest specific wear rate was measured as 0.3374 × 10-3 mm3·(Nm)-1 in the 3 wt% B4C+9 wt% SiC reinforced sample. © 2022 Walter de Gruyter GmbH, Berlin/Boston.
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    Properties of Aluminum Nano Composites Bearing Alumina Particles and Multiwall Carbon Nanotubes Manufactured by Mechanical Alloying and Microwave Sintering
    (Korean Institute of Metals and Materials, 2023) Özer E.; Ayvaz M.; Übeyli M.; Sarpkaya İ.
    Abstract: In this research, the effects of heat treatment and hybrid reinforcement ratio on the microstructural and mechanical properties of Al–4Cu nanocomposites containing MWCNT and nano Al2O3p were investigated. First of all, the hybrid reinforced Al–4Cu nanocomposites were manufactured with the aid of mechanical alloying and microwave sintering. And then, they were subjected to various heat treatments; annealing and artificial aging at 170, 180 and 200 °C individually. After that, the microstructural observations were made using X-ray diffraction, optical microscope and scanning electron microscopes (SEMs). The secondary electrons (SE), back scattered electrons (BSE), energy dispersive X-ray (EDX) and elemental mapping analyses of the specimens were carried out with the aid of SEMs. In addition, the nanoindentation tests were done to get the nanohardness and elastic modulus of composites. Finally, the composites were subjected to the compression test to clarify their compressive properties. The Al2Cu and Al4C3 precipitates were detected in the composite samples either annealed or peak-aged at 200 °C, while the intermetallic compound, Al7Cu2Fe, precipitated only in the aged samples. A significant increment in the nanohardness of composites was obtained with increasing reinforcement content. Moreover, the elastic modulus of annealed and peak-aged composites, reinforced with 15% hybrid reinforcement in volume, increased by 59% and 57%, respectively compared to the unreinforced alloy. Furthermore, the use of hybrid reinforcement in the alloy matrix allowed an improvement of compressive yield strength at the expense of compressive strain. Graphical Abstract: [Figure not available: see fulltext.]. © 2022, The Author(s) under exclusive licence to The Korean Institute of Metals and Materials.